20th Century Electricity power transmission was dominated by the Tesla and Westinghouse system of AC Alternating Current which won over the earlier Edison DC power distribution model, in part as power was generally generated remotely, transmitted efficiently over long distances via AC and at high voltage (to minimize conductor size and power law distribution losses, and HVDC conversion technology was not known then), and used for generally high load end device applications in domestic, office and factory locations via AC 110/240 v power circuitry and sockets, which remain the dominant in buildings today.
However 21st century requirements are changing, in both the production and consumption of energy as well as new environmental and conservation pressures, suggesting a new architecture for power provision and control in buildings.
Today many renewable technologies, localized storage, local distributed generation or home micro-generation/CHP technologies are available or emerging that can provide power closer to end loads, for example some can be placed a few meters away in households so have advantages of reducing distribution loss issues. Similarly they have potential to reduce conversion loss as several technologies, such as storage, solar photo-voltaics produce DC output directly negating the losses from rectifying/inverting to AC if it can be connected directly to suitable end loads. However, significant challenges in physically implementing such renewable solutions (and particularly low cost micro-generators as well as mini generators or energy scavengers providing only small amounts of power) in every day houses and building circuitry remain; such as controlling and connecting into existing building circuitry, designing for easy ‘Plug/Play’ application in the context of a lack of common voltage or other standards in end devices and supply, or measuring suitable circuit/device load opportunities for intermittent renewable supplies, consumer ease and cost of change, and matching solutions to consumers and usage type and achievable consumer change behaviour, as well as timing and choosing to deploy or retro-fit such solutions cost effectively within the limits of the current technology adequacy level and apply them to the right end applications vs. intermediary up-grade paths or migration points or developing new build approaches as new technology becomes available.
Similarly the modern end load requirement is changing in terms of where and what electricity is used for. Modern electronic devices, particularly consumer and portable electronics, lighting technologies (e.g. LED/OLED) are increasingly low power and DC. They are also proliferating as electronics is embedded into more and more devices such that consumers today have significant number of DC devices, each requiring dedicated cables, AC/DC adaptors to draw power, or internal power converters, or are battery operated with dedicated charger stations or use removable disposable batteries. Frequently devices are inefficiently connected to power supply, as cables, batteries and chargers, adaptors traditionally have a low cost focus and high AC/DC losses, or have poor power control (are frequently left on a power consuming standby mode, or are always on even when not utilized), or are not standardized or capable of tolerating or converting supply voltage differences or using universal adaptors, and consequentially clog up limited AC socket space or cause wiring hazards or portable inconvenience, have high churn as dedicated and obsolete with the device wasting precious natural resources and materials. It is estimated that in excess of 10 billion adaptors are in use worldwide, wasting 2-3% of national electricity in power conversion alone (and further loses with standby inefficiency), and each year over a billion adaptors go into landfill, along with over 15 billion disposable batteries.
This shift towards low power DC is set to continue with proliferation of phone/portable electronic devices, lighting and with devices themselves becoming more energy efficient, particularly as advances in semi-conductor and nanotechnology enable ever smaller intelligent or embedded devices, and the centralization of services (see below). The result is that at the household level a majority of devices will be low load DC, yet the problem of connectivity to the legacy grid/domestic AC supply is significant—it is not designed or optimal for an increasingly DC future.
These problems prompt the need, which the invention (among other things) provides means to address, for better provision of low power DC supply in building circuitry to co-exist alongside or partially replace AC circuitry—which is still required for traditional legacy high load devices such as cooking/washing/heating appliances, lighting pre migration to more efficient solutions, electric vehicles or highly mechanical/electric motor based devices, and adolescent product categories (many technologies often emerge first as high load but become more efficient on power over decades e.g. TVs from CRT to LCD to OLED, or music from mechanical to digital, lighting from incandescent to CFL to LED/OLED). Said low power provision may include dedicated wiring or wiring re-use, renewables integration, points of efficient AC/DC conversion, sub-loop circuits of localized DC power, DC power servers or sockets and suitable control, variable voltage capability and storage means.
Some of these problems have previously led to using alternate dedicated wiring, such as the legacy phone network, Ethernet to act as a low power source commonly referred to as ‘PoE—Power over Ethernet’ around a 48 v supply level, and other standards such as the Universal Serial Port—USB, however, such approaches have generally required dedicated wiring, cable length restrictions and load limits (e.g. PoE 12-15 W, USB 0.5-2.5 W/4 m) however, they play a role in the overall architecture for power provision of the invention given the universal benefit of end connectors such as Ethernet and USB for end socket loads, as do similar classes of power connector adaptors (typically found on 9V AC/DC adaptors for computers, or 3-5 v adaptors for mobile phones).
Whilst such proposals of power over Ethernet or USB protocol for power provision have largely focused on selected devices and not on how such systems could be aligned against AC circuits, particularly domestic circuits, or to incorporate renewables and a wide range of end devices with different voltage requirements.
Another factor in power provision is the changing trends in where energy is consumed or devices are charged. Many low power devices are portable, so a small but increasing proportion of a consumers energy e.g. laptops/phones, is now ‘carried’ and relies on wasteful disposable batteries or re-charging at different locations—which has already resulted in one company (a budget airline) banning staff from charging personal mobile phones in offices as passing costs to the employer. Electric vehicle storage batteries may charge from dedicated stations, or swap over batteries at charge banks, or overnight charging at homes (when power is cheaper or when directed to be charged by intelligent vehicle to grid V2G or smart grid load balancing systems), and may also have the capability (supported by the invention) to provide power back to the home for suitable DC/low load applications, or as per prior art (e.g. Google/Gridpoint vehicle/direct response systems) to provide power back to the grid under ‘direct response’ systems that also seek to balance peak energy requirements by turning off systems (e.g. HVAC) that have been pre-allocated as low priority to prevent the need to have built additional network generation capacity for peaks. Similar Fuel cell/hybrid cars may also act to provide power into homes or smart grid systems, and smaller scale fuel cells in CHP systems or as portable fuel cells may also have the ability to act as charging stations or provide supply into circuitry.
A further relevant trend is an overall virtualization of products and services, and a centralization of data and application provision in data centres or the wider network under cloud computing. As a result power consumption in data centres is growing significantly (e.g. exceeded 1.5% of total US consumption in 2006), along with power required to support constant 24×7 uptime and access at high bandwidth across physical and mobile networks. On one level this shifts energy consumption more centrally from homes/offices to central locations as end computing devices become ‘thin clients’ both in processing/storage as well as in energy requirements however, this is partly balanced by the trend to leave computers as well as broadband and wireless routers on constantly. This trend reflects consumers increasingly outsourcing activities to the network—such as memory or basic organization (mapping information, diary/contact details, basic information/search) and services which may not always have positive energy reduction trade-offs, even though the invention discloses capabilities to similarly enable energy management to be outsourced to third parties and web services to drive efficiency gains. A similar transition and trade-off has occurred in product virtualization and moving to solid state devices, such as in music apparatus, where current low power music devices such as MP3 (e.g. 160 m+ iPod devices), are significantly energy and materials efficient compared to the electric motor and oil (DVD/CD/Vinyl/Tape) based music apparatus of the past, so arguably shifts power use from the home to data centres supporting libraries of downloadable content—but has the overall result of dramatically reducing the world wide energy and resource requirement that would have previously been required to service 160 m+ consumers worth of music consumption. Similar trends are likely across other technology categories, which may further shrink some domestic energy requirements and shift into data centres—which are themselves significantly investing in how to best maximize DC power provision to server racks, and also optimized co-location with renewable supplies or centralized power generation.
Such Data Centre investments and new DC distribution architectures and power conversion circuitry can also, according to the invention, translate back to distributed generation technologies at the local and street level to provide optimized AC/step down, and DC distribution in neighbourhoods direct to houses/residential units for suitable loads, since an average data centre server rack cabinet now consumes many multiples of the average European household electricity load. Consequentially each server rack can be viewed loosely as equivalent to several houses, and several terraced streets or tower blocks as equivalent to a row of server racks. Knowledge of DC load requirements, circuit taxonomy and device type and usage, according to the invention, provide mechanisms to optimize and determine the viability of local distributed generation capacity and DC provision for supplying distributed loads across houses (e.g. thin-computing, network access, media devices, LED lighting) as well as direct response/control/balancing opportunities in overall energy management.
A key challenge to renewable integration is the trade-off and cost-benefit calculation on whether implantation makes sense, particularly with the current efficiency and cost level of certain technologies. Whilst remote power generation, such as coal might be 60% inefficient, with approx 5% further lost in transmission, installing local micro-generation (such as solar) to enable all devices to be powered off-grid in homes, is frequently wrong on cost-benefit, due to the high cost of generating capacity to cope with peak loads, the intermittent nature of solar, and the overall loss when inverting up to AC. In fact it rarely makes sense except for lower load DC application, where such loads should be identified and powered directly as per the invention, without a necessity to convert to AC and down to DC again, and where such renewable implementations should be sized up to only the appropriate load levels where they make sense. Similarly some renewable, localized storage/V2G systems may make sense in a supporting role for high load domestic requirements or as overall local generation, but might be ruled out on efficiency and cost terms compared to higher efficiencies at higher outputs available in some traditional centralized power systems.
Whilst some intelligent systems for energy management have been proposed (e.g. Gridpoint), or. those involved in direct response management, most focus has been on remotely controlling and shutting down these resources to free up available capacity for elsewhere on the network, rather than attempts to reduce or remove such loads from the system or migrate them to appropriate DC supply or renewable sources.
A key to assessing and determining which technologies and distribution architecture to employs, is measuring precise information on energy usage, patterns of behaviour and circuit, device power requirements and usage, to enable an optimal balance between remote grid based power, local distributed generation and microgen supply and intelligent DC provision in circuitry. More particularly, detailed measurement of how and what AC or high loads are used, enables opportunities to provide advice, substitution or intelligent control to reduce their overall energy use.
Steps have been taken towards better measurement at the household level via Smart Meters or AMI—Advance Metering Infrastructure, where communication is embedded into a utility meter to measure/report usage at higher granularity back to the utility supplier to provide progressively, communication to supplier systems, Automatic meter reading (AMR), more accurate/granular electronic billing as well as ROC/REC environmental claims on energy savings, fault or service analysis, time based tariffs, two-way communication—e.g. facilitating some direct response activity, or direct control (e.g. staged restarts following outages). Such communication has employed numerous forms of communication from proximity touch or RF technology via hand-helds or drive by mobile systems, powerline via sending signals over the power infrastructure to base stations, or fixed network via antennas, collectors or repeaters (including mesh networks where meters themselves act as repeaters—typically via wireless protocols such as Zigbee, or mobile phone networks).
Systems also exist to provide such overall usage data back to consumers in intervals or real-time, either by local displays connected directly via powerline or local communication means to the meter, or via web access and live data updates from real-time monitoring by the energy supplier (GE example), but more typically through independent devices generally comprising of a current sensor attached onto mains cables from the utility meter (e.g. Sentec GB0207383.1), a local communication means and a consumer device/display, set-top box or computer, where usage data is typically shown in an estimated energy cost, unit cost, or environmental measure (e.g. estimated C02 emissions). Some devices capture/store information enabling comparison or provide a live or batch link to a computer resource to enable more analysis. Few provide information other than crudely, or in aggregate on how the energy is being consumed, however the portable nature of many displays does enable consumers to walk around and see the impact of turning/on or off some appliances to see the corresponding change in real-time energy use, that supports education/awareness benefits to consumers. Other systems rely on sensors in each circuit or switch (e.g. Deep Stream), adaptors/plugs, that can capture the usage of the device connected to the plug, or high cost systems involving multiple sensors in sockets/devices and appliances communicating via wireless protocols, powerline or other means. However, the invention provides improvements in monitoring and sensor architecture, benefits of segmenting and leveraging selective sensors—e.g. embedded in individual or primary circuit breakers (RCD/MCB) at the fuse box level, analysis and disaggregation of load, device inference, software monitoring, phase interference, calibration, and other means in combination, or with correlation with other utility usage measurement. The invention provides measures to recognize and overcome different consumer change psychology that has prevented past renewable installations and energy changes being effective in real situations.
Despite the substantial and numerous prior art and abundance of individual power technologies, renewable technologies and sensing apparatus, few address the problems outlined here or provide the benefits of an overall integrated approach to providing hybrid AC/DC, and variable voltage and end point conversion, ease of installation into an established environment and inclusion of micro and suitable renewables, and overall sensing apparatus, inference and deductions said architecture and systems allow to enable change and savings.